Question…

I have a 2008 outlander 500, <1000 miles, low hours, never in mud/water.

A few days ago it acted like it had an injector plugging, I added sea foam to the fuel and figured it would clear it up over a few days. For the next several days I’d run it a little each day, it got worse, running about 1/2 it’s power and wouldn’t do over 25mph.

Today I pulled plugs, they looked good, just for the heck of it I cranked it with the rear plug wire pulled and it ran like it has been the past few days, so it has only been running on one cylinder but every once in a while both would run and it would act normal, but not for long. And this evening it will only run on 1 cylinder.

What do you think I should check 1st? I’ve checked battery voltage, it’s good >12.8, plugs look good, but I’m going to replace them tommorow. Both plugs have fire….

Injector for rear cylinder maybe bad? Any way to check them ?

Will a fuel pump that’s going out make it only run in 1 cylinder?

Thanks in advance for any replies.